This rare devotional shrine manifests Christian belief in the miracle of the Incarnation, by which God took on human body and nature, uniting both human and divine in the person of Jesus. Closed, it is a statuette of the enthroned Virgin Mary nursing the infant Jesus. When opened, the shrine is transformed into an altarpiece showing a sculptural representation of the Trinity. (Only the figure of God the father remains; lost are the figures of Christ and the dove representing the Holy Spirit, the second and third persons of the Trinity.) Painted scenes of the Nativity decorate the wings.

Bynum, Caroline Walker. "The Female Body and Religious Practice in the Later Middle Ages." In Fragmentation and Redemption: Essays on Gender and the Human Body in Medieval Religion. New York: Zone Books, 1991. p. 212, fig. 6.11.